diff --git a/source/m3_api_libc.c b/source/m3_api_libc.c
index 32dee82..e3fe73d 100644
--- a/source/m3_api_libc.c
+++ b/source/m3_api_libc.c
@@ -39,6 +39,8 @@ m3ApiRawFunction(m3_libc_memset)
     m3ApiGetArg     (int32_t, i_value)
     m3ApiGetArg     (int32_t, i_size)
 
+    m3ApiCheckMem(i_ptr, i_size);
+
     u32 result = m3ApiPtrToOffset(memset (i_ptr, i_value, i_size));
     m3ApiReturn(result);
 }
@@ -51,6 +53,9 @@ m3ApiRawFunction(m3_libc_memmove)
     m3ApiGetArgMem  (void*,   i_src)
     m3ApiGetArg     (int32_t, i_size)
 
+    m3ApiCheckMem(o_dst, i_size);
+    m3ApiCheckMem(i_src, i_size);
+
     u32 result = m3ApiPtrToOffset(memmove (o_dst, i_src, i_size));
     m3ApiReturn(result);
 }
@@ -62,6 +67,8 @@ m3ApiRawFunction(m3_libc_print)
     m3ApiGetArgMem  (void*,    i_ptr)
     m3ApiGetArg     (uint32_t, i_size)
 
+    m3ApiCheckMem(i_ptr, i_size);
+
     fwrite(i_ptr, i_size, 1, stdout);
     fflush(stdout);
 
@@ -89,33 +96,11 @@ m3ApiRawFunction(m3_spectest_dummy)
     m3ApiSuccess();
 }
 
-m3ApiRawFunction(m3_wasm3_raw_sum)
-{
-    m3ApiReturnType  (int64_t)
-    m3ApiGetArg      (int32_t, val1)
-    m3ApiGetArg      (int32_t, val2)
-    m3ApiGetArg      (int32_t, val3)
-    m3ApiGetArg      (int32_t, val4)
-
-    m3ApiReturn(val1 + val2 + val3 + val4);
-
-    m3ApiSuccess();
-}
-
-/* TODO: implement direct native function calls (using libffi?)
-i64 m3_wasm3_native_sum(i32 val1, i32 val2, i32 val3, i32 val4)
-{
-    return val1 + val2 + val3 + val4;
-}
-*/
-
-
 M3Result  m3_LinkSpecTest  (IM3Module module)
 {
     M3Result result = m3Err_none;
 
     const char* spectest = "spectest";
-    const char* wasm3    = "wasm3";
 
 _   (SuppressLookupFailure (m3_LinkRawFunction (module, spectest, "print",         "v()",      &m3_spectest_dummy)));
 _   (SuppressLookupFailure (m3_LinkRawFunction (module, spectest, "print_i32",     "v(i)",     &m3_spectest_dummy)));
@@ -125,10 +110,6 @@ _   (SuppressLookupFailure (m3_LinkRawFunction (module, spectest, "print_f64",
 _   (SuppressLookupFailure (m3_LinkRawFunction (module, spectest, "print_i32_f32", "v(if)",    &m3_spectest_dummy)));
 _   (SuppressLookupFailure (m3_LinkRawFunction (module, spectest, "print_i64_f64", "v(IF)",    &m3_spectest_dummy)));
 
-
-_   (SuppressLookupFailure (m3_LinkRawFunction (module, wasm3, "raw_sum",          "I(iiii)",  &m3_wasm3_raw_sum)));
-//_   (SuppressLookupFailure (m3_LinkCFunction   (module, wasm3, "native_sum",    "I(iiii)",  &m3_wasm3_native_sum)));
-
 _catch:
     return result;
 }