diff --git a/.gitignore b/.gitignore
index 75d7597a..0f4e302c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,3 +31,6 @@ xcuserdata
 
 # Carthage
 Carthage/Build
+
+# Pre-action log file
+pre_action.log
\ No newline at end of file
diff --git a/LibWally.xcodeproj/project.pbxproj b/LibWally.xcodeproj/project.pbxproj
index 4479f90c..a22e4f6d 100644
--- a/LibWally.xcodeproj/project.pbxproj
+++ b/LibWally.xcodeproj/project.pbxproj
@@ -3,7 +3,7 @@
 	archiveVersion = 1;
 	classes = {
 	};
-	objectVersion = 50;
+	objectVersion = 52;
 	objects = {
 
 /* Begin PBXBuildFile section */
@@ -58,7 +58,6 @@
 		FE9CD3BA229C397900345DFA /* LibWallyTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = LibWallyTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 		FE9CD3BF229C397900345DFA /* BIP39Tests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BIP39Tests.swift; sourceTree = "<group>"; };
 		FE9CD3C1229C397900345DFA /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
-		FEB0B872229C72A700459518 /* libwallycore.a */ = {isa = PBXFileReference; lastKnownFileType = archive.ar; name = libwallycore.a; path = "libwally-core/src/.libs/libwallycore.a"; sourceTree = "<group>"; };
 		FEC79CE3229E7F3800D86E2E /* BIP32.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BIP32.swift; sourceTree = "<group>"; };
 		FEC79CE5229E807500D86E2E /* BIP32Tests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BIP32Tests.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
@@ -140,7 +139,6 @@
 			isa = PBXGroup;
 			children = (
 				A20C942422C6BC3900B0D206 /* libwallycore.a */,
-				FEB0B872229C72A700459518 /* libwallycore.a */,
 			);
 			name = Frameworks;
 			sourceTree = "<group>";
@@ -215,7 +213,7 @@
 				};
 			};
 			buildConfigurationList = FE9CD3AB229C397900345DFA /* Build configuration list for PBXProject "LibWally" */;
-			compatibilityVersion = "Xcode 9.3";
+			compatibilityVersion = "Xcode 11.0";
 			developmentRegion = en;
 			hasScannedForEncodings = 0;
 			knownRegions = (
@@ -294,6 +292,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
+				BUILD_LIB_WALLY_CORE = NO;
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
@@ -359,6 +358,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
+				BUILD_LIB_WALLY_CORE = NO;
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
@@ -419,7 +419,7 @@
 			buildSettings = {
 				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_IDENTITY = "";
-				CODE_SIGN_STYLE = Automatic;
+				CODE_SIGN_STYLE = Manual;
 				DEFINES_MODULE = YES;
 				DEVELOPMENT_TEAM = "";
 				DYLIB_COMPATIBILITY_VERSION = 1;
@@ -435,14 +435,13 @@
 				);
 				LIBRARY_SEARCH_PATHS = (
 					"$(inherited)",
-					"$(PROJECT_DIR)/libwally-core/src/secp256k1/.libs",
-					"$(PROJECT_DIR)/libwally-core/src/.libs",
-					"$(PROJECT_DIR)/libwally-core/dist",
 					"$(PROJECT_DIR)/CLibWally/libwally-core/src/.libs",
 				);
 				MODULEMAP_FILE = "$(SRCROOT)/LibWally/LibWally.modulemap";
 				PRODUCT_BUNDLE_IDENTIFIER = com.blockchain.LibWally;
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
+				PROVISIONING_PROFILE_SPECIFIER = "";
+				"PROVISIONING_PROFILE_SPECIFIER[sdk=macosx*]" = "";
 				SKIP_INSTALL = YES;
 				SWIFT_INCLUDE_PATHS = "${SRCROOT}/CLibWally";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
@@ -456,7 +455,7 @@
 			buildSettings = {
 				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_IDENTITY = "";
-				CODE_SIGN_STYLE = Automatic;
+				CODE_SIGN_STYLE = Manual;
 				DEFINES_MODULE = YES;
 				DEVELOPMENT_TEAM = "";
 				DYLIB_COMPATIBILITY_VERSION = 1;
@@ -472,14 +471,13 @@
 				);
 				LIBRARY_SEARCH_PATHS = (
 					"$(inherited)",
-					"$(PROJECT_DIR)/libwally-core/src/secp256k1/.libs",
-					"$(PROJECT_DIR)/libwally-core/src/.libs",
-					"$(PROJECT_DIR)/libwally-core/dist",
 					"$(PROJECT_DIR)/CLibWally/libwally-core/src/.libs",
 				);
 				MODULEMAP_FILE = "$(SRCROOT)/LibWally/LibWally.modulemap";
 				PRODUCT_BUNDLE_IDENTIFIER = com.blockchain.LibWally;
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
+				PROVISIONING_PROFILE_SPECIFIER = "";
+				"PROVISIONING_PROFILE_SPECIFIER[sdk=macosx*]" = "";
 				SKIP_INSTALL = YES;
 				SWIFT_INCLUDE_PATHS = "${SRCROOT}/CLibWally";
 				SWIFT_VERSION = 5.0;
@@ -491,8 +489,9 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
-				CODE_SIGN_STYLE = Automatic;
-				DEVELOPMENT_TEAM = NZ6PH75U7K;
+				CODE_SIGN_IDENTITY = "";
+				CODE_SIGN_STYLE = Manual;
+				DEVELOPMENT_TEAM = "";
 				INFOPLIST_FILE = LibWallyTests/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
@@ -501,6 +500,8 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.blockchain.LibWallyTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				PROVISIONING_PROFILE_SPECIFIER = "";
+				"PROVISIONING_PROFILE_SPECIFIER[sdk=macosx*]" = "";
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
@@ -510,8 +511,9 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
-				CODE_SIGN_STYLE = Automatic;
-				DEVELOPMENT_TEAM = NZ6PH75U7K;
+				CODE_SIGN_IDENTITY = "";
+				CODE_SIGN_STYLE = Manual;
+				DEVELOPMENT_TEAM = "";
 				INFOPLIST_FILE = LibWallyTests/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
@@ -520,6 +522,8 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.blockchain.LibWallyTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				PROVISIONING_PROFILE_SPECIFIER = "";
+				"PROVISIONING_PROFILE_SPECIFIER[sdk=macosx*]" = "";
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
diff --git a/LibWally.xcodeproj/xcshareddata/xcschemes/LibWally.xcscheme b/LibWally.xcodeproj/xcshareddata/xcschemes/LibWally.xcscheme
index 249d8adb..7b4003c1 100644
--- a/LibWally.xcodeproj/xcshareddata/xcschemes/LibWally.xcscheme
+++ b/LibWally.xcodeproj/xcshareddata/xcschemes/LibWally.xcscheme
@@ -1,10 +1,28 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1020"
-   version = "1.3">
+   LastUpgradeVersion = "1140"
+   version = "1.7">
    <BuildAction
       parallelizeBuildables = "YES"
       buildImplicitDependencies = "YES">
+      <PreActions>
+         <ExecutionAction
+            ActionType = "Xcode.IDEStandardExecutionActionsCore.ExecutionActionType.ShellScriptAction">
+            <ActionContent
+               title = "Run Script"
+               scriptText = "# Builds libwallycore.a for simulator and device if necessary&#10;exec &gt; $PROJECT_DIR/pre_action.log 2&gt;&amp;1&#10;if [[ $CARTHAGE == &quot;YES&quot; ]] || [[ $BUILD_LIB_WALLY_CORE == &quot;YES&quot; ]]; then&#10;    cd $PROJECT_DIR&#10;    echo &quot;Starting build scheme Pre-actions&quot;&#10;    &quot;${PROJECT_DIR}/carthage-build-libwally.sh&quot;&#10;else&#10;    echo &quot;Build scheme Pre-actions skipped, not Carthage&quot;&#10;fi&#10;">
+               <EnvironmentBuildable>
+                  <BuildableReference
+                     BuildableIdentifier = "primary"
+                     BlueprintIdentifier = "FE9CD3B0229C397900345DFA"
+                     BuildableName = "LibWally.framework"
+                     BlueprintName = "LibWally"
+                     ReferencedContainer = "container:LibWally.xcodeproj">
+                  </BuildableReference>
+               </EnvironmentBuildable>
+            </ActionContent>
+         </ExecutionAction>
+      </PreActions>
       <BuildActionEntries>
          <BuildActionEntry
             buildForTesting = "YES"
@@ -39,17 +57,6 @@
             </BuildableReference>
          </TestableReference>
       </Testables>
-      <MacroExpansion>
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "FE9CD3B0229C397900345DFA"
-            BuildableName = "LibWally.framework"
-            BlueprintName = "LibWally"
-            ReferencedContainer = "container:LibWally.xcodeproj">
-         </BuildableReference>
-      </MacroExpansion>
-      <AdditionalOptions>
-      </AdditionalOptions>
    </TestAction>
    <LaunchAction
       buildConfiguration = "Debug"
@@ -61,17 +68,6 @@
       debugDocumentVersioning = "YES"
       debugServiceExtension = "internal"
       allowLocationSimulation = "YES">
-      <MacroExpansion>
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "FE9CD3B0229C397900345DFA"
-            BuildableName = "LibWally.framework"
-            BlueprintName = "LibWally"
-            ReferencedContainer = "container:LibWally.xcodeproj">
-         </BuildableReference>
-      </MacroExpansion>
-      <AdditionalOptions>
-      </AdditionalOptions>
    </LaunchAction>
    <ProfileAction
       buildConfiguration = "Release"
diff --git a/carthage-build-libwally.sh b/carthage-build-libwally.sh
new file mode 100755
index 00000000..6fe9f2d0
--- /dev/null
+++ b/carthage-build-libwally.sh
@@ -0,0 +1,29 @@
+#!/usr/bin/env sh
+set -e # abort if any command fails
+
+LIBWALLYCORE="CLibWally/libwally-core/src/.libs/libwallycore.a"
+VALIDLIBWALLYCORE=0
+REQUIREDARCHS="armv7 armv7s i386 x86_64 arm64 arm64e"
+LIPO_CMD="lipo $LIBWALLYCORE -verify_arch $REQUIREDARCHS"
+
+if [ -e "$LIBWALLYCORE" ]; then
+    echo "$LIBWALLYCORE exists"
+    if $LIPO_CMD; then
+        VALIDLIBWALLYCORE=1
+        echo "libwallycore.a contains $REQUIREDARCHS"
+    else
+        echo "libwallycore.a does not contain $REQUIREDARCHS"
+        lipo "$LIBWALLYCORE" -info
+    fi
+else
+    echo "$LIBWALLYCORE does not exists"
+fi
+
+if ((VALIDLIBWALLYCORE == 0)); then
+    echo "Rebuilding libwallycore.a"
+    sh ./build-libwally.sh -csd
+else
+    echo "Skip rebuild"
+fi
+
+exit 0