diff --git a/crypto/fipsmodule/cpucap/cpu_intel.c b/crypto/fipsmodule/cpucap/cpu_intel.c
index e236e3e6999..5e469ad2c49 100644
--- a/crypto/fipsmodule/cpucap/cpu_intel.c
+++ b/crypto/fipsmodule/cpucap/cpu_intel.c
@@ -133,6 +133,8 @@ static void handle_cpu_env(uint32_t *out, const char *in) {
   const int or = in[0] == '|';
   const int skip_first_byte = invert || or;
   const int hex = in[skip_first_byte] == '0' && in[skip_first_byte+1] == 'x';
+  uint32_t intelcap0 = out[0];
+  uint32_t intelcap1 = out[1];
 
   int sscanf_result;
   uint64_t v;
@@ -146,15 +148,31 @@ static void handle_cpu_env(uint32_t *out, const char *in) {
     return;
   }
 
+  uint32_t reqcap0 = (uint32_t)(v & UINT32_MAX);
+  uint32_t reqcap1 = (uint32_t)(v >> 32);
+
+  // Detect if the user is trying to use the environment variable to set
+  // a capability that is _not_ available on the CPU.
+  // The case of invert cannot enable an unexisting capability;
+  // it can only disable an existing one.
+  if (!invert && (intelcap0 || intelcap1)) {
+    if((~intelcap0 & reqcap0) || (~intelcap1 & reqcap1)) {
+      fprintf(stderr,
+              "Fatal Error: HW capability found: 0x%02X 0x%02X, but HW capability requested: 0x%02X 0x%02X.\n",
+              intelcap0, intelcap1, reqcap0, reqcap1);
+      abort();
+    }
+  }
+
   if (invert) {
-    out[0] &= ~v;
-    out[1] &= ~(v >> 32);
+    out[0] &= ~reqcap0;
+    out[1] &= ~reqcap1;
   } else if (or) {
-    out[0] |= v;
-    out[1] |= (v >> 32);
+    out[0] |= reqcap0;
+    out[1] |= reqcap1;
   } else {
-    out[0] = v;
-    out[1] = v >> 32;
+    out[0] = reqcap0;
+    out[1] = reqcap1;
   }
 }
 
diff --git a/crypto/fipsmodule/cpucap/cpu_ppc64le.c b/crypto/fipsmodule/cpucap/cpu_ppc64le.c
index e9e9891fe39..237964915ae 100644
--- a/crypto/fipsmodule/cpucap/cpu_ppc64le.c
+++ b/crypto/fipsmodule/cpucap/cpu_ppc64le.c
@@ -31,25 +31,37 @@ static void handle_cpu_env(unsigned long *out, const char *in) {
   const int or = in[0] == '|';
   const int skip_first_byte = (invert || or) ? 1 : 0;
   const int hex = in[skip_first_byte] == '0' && in[skip_first_byte+1] == 'x';
+  unsigned long ppccap = *out;
 
   int sscanf_result;
-  uint64_t v;
+  uint64_t reqcap;
   if (hex) {
-    sscanf_result = sscanf(in + skip_first_byte + 2, "%" PRIx64, &v);
+    sscanf_result = sscanf(in + skip_first_byte + 2, "%" PRIx64, &reqcap);
   } else {
-    sscanf_result = sscanf(in + skip_first_byte, "%" PRIu64, &v);
+    sscanf_result = sscanf(in + skip_first_byte, "%" PRIu64, &reqcap);
   }
 
   if (!sscanf_result) {
     return;
   }
 
+  // Detect if the user is trying to use the environment variable to set
+  // a capability that is _not_ available on the CPU.
+  // The case of invert cannot enable an unexisting capability;
+  // it can only disable an existing one.
+  if (!invert && ppccap && (~ppccap & reqcap)) {
+    fprintf(stderr,
+            "Fatal Error: HW capability found: 0x%02X, but HW capability requested: 0x%02X.\n",
+            ppccap, reqcap);
+    abort();
+  }
+
   if (invert) {
-    *out &= ~v;
+    *out &= ~reqcap;
   } else if (or) {
-    *out |= v;
+    *out |= reqcap;
   } else {
-    *out = v;
+    *out = reqcap;
   }
 }