diff --git a/ChangeLog b/ChangeLog
index 26509c52..5a0f2cda 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,7 @@
 Changes in primecount-7.14, 2024-06-19
 
 * int128_t.hpp: Rename namespace port to pstd (portable std namespace).
+* cpuid.hpp: Prevent memory reordering.
 * Sieve.hpp: Tune AVX512 code.
 * multiarch_avx512_vpopcnt.cmake: Tune AVX512 code.
 
diff --git a/include/cpuid.hpp b/include/cpuid.hpp
index 92b81002..87e85b13 100644
--- a/include/cpuid.hpp
+++ b/include/cpuid.hpp
@@ -28,19 +28,23 @@ inline void run_cpuid(int eax, int ecx, int* abcd)
   #if defined(__i386__) && \
       defined(__PIC__)
     /* in case of PIC under 32-bit EBX cannot be clobbered */
-    __asm__ ("movl %%ebx, %%edi;"
-             "cpuid;"
-             "xchgl %%ebx, %%edi;"
-             : "=D" (ebx),
-               "+a" (eax),
-               "+c" (ecx),
-               "=d" (edx));
+    __asm__ __volatile__ (
+      "movl %%ebx, %%edi;"
+      "cpuid;"
+      "xchgl %%ebx, %%edi;"
+      : "=D" (ebx),
+        "+a" (eax),
+        "+c" (ecx),
+        "=d" (edx)
+      : "memory"
+    );
   #else
-    __asm__ ("cpuid;"
-             : "+b" (ebx),
-               "+a" (eax),
-               "+c" (ecx),
-               "=d" (edx));
+    __asm__ __volatile__ (
+        "cpuid"
+        : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx)
+        : "0" (eax), "2" (ecx)
+        : "memory"
+    );
   #endif
 
   abcd[0] = eax;