diff --git a/GNUmakefile b/GNUmakefile
index 40700cc6..ae38c0a7 100755
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -668,6 +668,7 @@ ifeq ($(DETECT_FEATURES),1)
     BLAKE2S_FLAG = $(POWER7_FLAG)
     CHACHA_FLAG = $(POWER7_FLAG)
     CHAM_FLAG = $(POWER7_FLAG)
+    GCM_FLAG = $(POWER7_FLAG)
     LEA_FLAG = $(POWER7_FLAG)
     SIMECK_FLAG = $(POWER7_FLAG)
     SIMON64_FLAG = $(POWER7_FLAG)
diff --git a/gcm.cpp b/gcm.cpp
index 59236ac2..473477c4 100644
--- a/gcm.cpp
+++ b/gcm.cpp
@@ -75,8 +75,8 @@ extern void GCM_Xor16_SSE2(byte *a, const byte *b, const byte *c);
 extern void GCM_Xor16_NEON(byte *a, const byte *b, const byte *c);
 #endif
 
-#if CRYPTOPP_ALTIVEC_AVAILABLE
-extern void GCM_Xor16_ALTIVEC(byte *a, const byte *b, const byte *c);
+#if CRYPTOPP_POWER7_AVAILABLE
+extern void GCM_Xor16_POWER7(byte *a, const byte *b, const byte *c);
 #endif
 
 #if CRYPTOPP_CLMUL_AVAILABLE
@@ -213,11 +213,11 @@ void GCM_Base::SetKeyWithoutResync(const byte *userKey, size_t keylength, const
                     for (k=1; k<j; k++)
                         GCM_Xor16_NEON(mulTable+i*256*16+(j+k)*16, mulTable+i*256*16+j*16, mulTable+i*256*16+k*16);
             else
-#elif CRYPTOPP_ALTIVEC_AVAILABLE
-            if (HasAltivec())
+#elif CRYPTOPP_POWER7_AVAILABLE
+            if (HasPower7())
                 for (j=2; j<=0x80; j*=2)
                     for (k=1; k<j; k++)
-                        GCM_Xor16_ALTIVEC(mulTable+i*256*16+(j+k)*16, mulTable+i*256*16+j*16, mulTable+i*256*16+k*16);
+                        GCM_Xor16_POWER7(mulTable+i*256*16+(j+k)*16, mulTable+i*256*16+j*16, mulTable+i*256*16+k*16);
             else
 #endif
                 for (j=2; j<=0x80; j*=2)
@@ -277,13 +277,13 @@ void GCM_Base::SetKeyWithoutResync(const byte *userKey, size_t keylength, const
                         GCM_Xor16_NEON(mulTable+1024+i*256+(j+k)*16, mulTable+1024+i*256+j*16, mulTable+1024+i*256+k*16);
                     }
             else
-#elif CRYPTOPP_ALTIVEC_AVAILABLE
-            if (HasAltivec())
+#elif CRYPTOPP_POWER7_AVAILABLE
+            if (HasPower7())
                 for (j=2; j<=8; j*=2)
                     for (k=1; k<j; k++)
                     {
-                        GCM_Xor16_ALTIVEC(mulTable+i*256+(j+k)*16, mulTable+i*256+j*16, mulTable+i*256+k*16);
-                        GCM_Xor16_ALTIVEC(mulTable+1024+i*256+(j+k)*16, mulTable+1024+i*256+j*16, mulTable+1024+i*256+k*16);
+                        GCM_Xor16_POWER7(mulTable+i*256+(j+k)*16, mulTable+i*256+j*16, mulTable+i*256+k*16);
+                        GCM_Xor16_POWER7(mulTable+1024+i*256+(j+k)*16, mulTable+1024+i*256+j*16, mulTable+1024+i*256+k*16);
                     }
             else
 #endif
@@ -369,8 +369,8 @@ unsigned int GCM_Base::OptimalDataAlignment() const
         HasSSE2() ? 16 :
 #elif CRYPTOPP_ARM_NEON_AVAILABLE
         HasNEON() ? 4 :
-#elif CRYPTOPP_ALTIVEC_AVAILABLE
-        HasAltivec() ? 16 :
+#elif CRYPTOPP_POWER7_AVAILABLE
+        HasPower7() ? 16 :
 #endif
         GetBlockCipher().OptimalDataAlignment();
 }
diff --git a/gcm_simd.cpp b/gcm_simd.cpp
index 3e42f16b..b701f398 100644
--- a/gcm_simd.cpp
+++ b/gcm_simd.cpp
@@ -740,8 +740,8 @@ void GCM_ReverseHashBufferIfNeeded_CLMUL(byte *hashBuffer)
 
 // ***************************** POWER8 ***************************** //
 
-#if CRYPTOPP_ALTIVEC_AVAILABLE
-void GCM_Xor16_ALTIVEC(byte *a, const byte *b, const byte *c)
+#if CRYPTOPP_POWER7_AVAILABLE
+void GCM_Xor16_POWER7(byte *a, const byte *b, const byte *c)
 {
     VecStore(VecXor(VecLoad(b), VecLoad(c)), a);
 }