diff --git a/c/Makefile b/c/Makefile
index 7adef637..f2cff94f 100644
--- a/c/Makefile
+++ b/c/Makefile
@@ -70,7 +70,7 @@ clean:
 
 dist/c-lib.wasm: build/lib.c
 	@mkdir -p dist
-	@emcc build/lib.c -Wl,--whole-archive -DUNITY_END -O$(O) -o dist/c-lib.mjs
+	@emcc build/lib.c -Wl,--whole-archive -DUNITY_END -O$(O) -s EXPORTED_RUNTIME_METHODS="['UTF8ToString']" -o dist/c-lib.mjs
 
 build/lib.c: ../LICENSE
 	@mkdir -p build
diff --git a/cplusplus/Makefile b/cplusplus/Makefile
index a842df99..7296e63c 100644
--- a/cplusplus/Makefile
+++ b/cplusplus/Makefile
@@ -62,7 +62,7 @@ clean:
 
 dist/cp-lib.wasm: build/lib.cpp
 	@mkdir -p dist
-	@emcc build/lib.cpp -Wl,--whole-archive -DUNITY_END -O$(O) -o dist/cp-lib.mjs
+	@emcc build/lib.cpp -Wl,--whole-archive -DUNITY_END -O$(O) -s EXPORTED_RUNTIME_METHODS="['UTF8ToString']" -o dist/cp-lib.mjs
 
 build/lib.cpp: ../LICENSE
 	@mkdir -p build
diff --git a/docs/_static/test-c.html b/docs/_static/test-c.html
index ad951e23..222e5f07 100644
--- a/docs/_static/test-c.html
+++ b/docs/_static/test-c.html
@@ -29,7 +29,10 @@
             describe(`run test ${p}`, function() {
               this.timeout(Infinity);
               it(`should return ${expected}`, () => {
-                const answer = func();
+                let answer = func();
+                if (typeof expected === 'string') {
+                  answer = Module.UTF8ToString(answer);
+                }
                 console.log(p, answer, expected);
                 if (answer !== expected) {
                   throw new Error();
diff --git a/docs/_static/test-cp.html b/docs/_static/test-cp.html
index 400d8331..778e707d 100644
--- a/docs/_static/test-cp.html
+++ b/docs/_static/test-cp.html
@@ -28,7 +28,10 @@
             describe(`run test ${p}`, function() {
               this.timeout(Infinity);
               it(`should return ${expected}`, () => {
-                const answer = func();
+                let answer = func();
+                if (typeof expected === 'string') {
+                  answer = Module.UTF8ToString(answer);
+                }
                 console.log(p, answer, expected);
                 if (answer !== expected) {
                   throw new Error();