diff --git a/CMakeLists.txt b/CMakeLists.txt
index 146e507930706d8d779ce6a3977b39d7f9d9b78c..af1f64bd83e317f91670a19b3a95113639f59193 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -608,8 +608,8 @@ if(MSVC)
   set(ZIG2_LINK_FLAGS "/STACK:16777216 /FORCE:MULTIPLE")
 else()
   set(ZIG_WASM2C_COMPILE_FLAGS "-std=c99 -O2")
-  set(ZIG1_COMPILE_FLAGS "-std=c99 -Os")
-  set(ZIG2_COMPILE_FLAGS "-std=c99 -O0 -fno-sanitize=undefined -fno-stack-protector")
+  set(ZIG1_COMPILE_FLAGS "-std=c99 -Os -fno-strict-aliasing")
+  set(ZIG2_COMPILE_FLAGS "-std=c99 -O0 -fno-sanitize=undefined -fno-stack-protector -fno-strict-aliasing")
   # Must match the condition in build.zig.
   if(ZIG_HOST_TARGET_ARCH MATCHES "^(arm|thumb)(eb)?$" OR ZIG_HOST_TARGET_ARCH MATCHES "^powerpc(64)?(le)?$")
     set(ZIG1_COMPILE_FLAGS "${ZIG1_COMPILE_FLAGS} -ffunction-sections -fdata-sections")
diff --git a/bootstrap.c b/bootstrap.c
index 329a1af10e5d9c4c61d5dc851587c1d80c0e0aa5..ad4ccec54a67fd3b94f880d0669be25303afd14f 100644
--- a/bootstrap.c
+++ b/bootstrap.c
@@ -136,7 +136,7 @@ int main(int argc, char **argv) {
     }
     {
         const char *child_argv[] = {
-            cc, "-o", "zig1", "zig1.c", "stage1/wasi.c", "-std=c99", "-Os", "-lm", NULL,
+            cc, "-o", "zig1", "zig1.c", "stage1/wasi.c", "-std=c99", "-Os", "-fno-strict-aliasing", "-lm", NULL,
         };
         print_and_run(child_argv);
     }
@@ -213,6 +213,7 @@ int main(int argc, char **argv) {
 #if defined(__GNUC__)
             "-pthread",
 #endif
+            "-fno-strict-aliasing",
             workaround_gcc_sra_miscomp ? "-fno-tree-sra" : NULL,
             NULL,
         };