diff --git a/IlmBase/config/CMakeLists.txt b/IlmBase/config/CMakeLists.txt
index dfebb43bd0..4e7ebabdc3 100644
--- a/IlmBase/config/CMakeLists.txt
+++ b/IlmBase/config/CMakeLists.txt
@@ -76,8 +76,8 @@ if(ILMBASE_INSTALL_PKG_CONFIG)
   function(ilmbase_pkg_config_help pcinfile)
     set(prefix ${CMAKE_INSTALL_PREFIX})
     set(exec_prefix "\${prefix}")
-    set(libdir "\${exec_prefix}/${CMAKE_INSTALL_LIBDIR}")
-    set(includedir "\${prefix}/${CMAKE_INSTALL_INCLUDEDIR}")
+    set(libdir ${CMAKE_INSTALL_FULL_LIBDIR})
+    set(includedir ${CMAKE_INSTALL_FULL_INCLUDEDIR})
     string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
     set(LIB_SUFFIX_DASH ${ILMBASE_LIB_SUFFIX}${CMAKE_${uppercase_CMAKE_BUILD_TYPE}_POSTFIX})
     if(TARGET Threads::Threads)
diff --git a/OpenEXR/config/CMakeLists.txt b/OpenEXR/config/CMakeLists.txt
index 039190cd90..940af048bf 100644
--- a/OpenEXR/config/CMakeLists.txt
+++ b/OpenEXR/config/CMakeLists.txt
@@ -75,8 +75,8 @@ if(OPENEXR_INSTALL_PKG_CONFIG)
   function(openexr_pkg_config_help pcinfile)
     set(prefix ${CMAKE_INSTALL_PREFIX})
     set(exec_prefix "\${prefix}")
-    set(libdir "\${exec_prefix}/${CMAKE_INSTALL_LIBDIR}")
-    set(includedir "\${prefix}/${CMAKE_INSTALL_INCLUDEDIR}")
+    set(libdir ${CMAKE_INSTALL_FULL_LIBDIR})
+    set(includedir ${CMAKE_INSTALL_FULL_INCLUDEDIR})
     string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
     set(LIB_SUFFIX_DASH ${OPENEXR_LIB_SUFFIX}${CMAKE_${uppercase_CMAKE_BUILD_TYPE}_POSTFIX})
     if(TARGET Threads::Threads)
diff --git a/PyIlmBase/config/CMakeLists.txt b/PyIlmBase/config/CMakeLists.txt
index a4139bcfd0..4b1b578352 100644
--- a/PyIlmBase/config/CMakeLists.txt
+++ b/PyIlmBase/config/CMakeLists.txt
@@ -16,8 +16,8 @@ if(PYILMBASE_INSTALL_PKG_CONFIG)
   function(pyilmbase_pkg_config_help pcinfile)
     set(prefix ${CMAKE_INSTALL_PREFIX})
     set(exec_prefix ${CMAKE_INSTALL_BINDIR})
-    set(libdir ${CMAKE_INSTALL_LIBDIR})
-    set(includedir ${CMAKE_INSTALL_INCLUDEDIR})
+    set(libdir ${CMAKE_INSTALL_FULL_LIBDIR})
+    set(includedir ${CMAKE_INSTALL_FULL_INCLUDEDIR})
     string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
     set(LIB_SUFFIX_DASH ${OPENEXR_LIB_SUFFIX}${CMAKE_${uppercase_CMAKE_BUILD_TYPE}_POSTFIX})
     string(REPLACE ".in" "" pcout ${pcinfile})