diff --git a/hscutl.c b/hscutl.c
index 870e6792..4c53ed6a 100644
--- a/hscutl.c
+++ b/hscutl.c
@@ -2592,7 +2592,9 @@ DLL_EXPORT bool are_big_endian()
 
 #if !defined( _MSVC_ ) // Linux, etc..
 
+#if !defined( __EMSCRIPTEN__ )  /* (no sys/ptrace.h in Emscripten) */
 #include <sys/ptrace.h>
+#endif
 
 #if defined( __APPLE__ ) || defined( __FreeBSD__ )
   #include <sys/sysctl.h>
@@ -2671,6 +2673,12 @@ static bool IsDebuggerPresent()
 
     return debugger_is_present;
 
+#elif defined( __EMSCRIPTEN__ )
+
+    // WebAssembly: no process tracing
+
+    return false;
+
 #endif
 
 } // IsDebuggerPresent