diff --git a/bin/confgen/Makefile.in b/bin/confgen/Makefile.in
index d2a6b692b3..83daebfe4a 100644
--- a/bin/confgen/Makefile.in
+++ b/bin/confgen/Makefile.in
@@ -22,7 +22,7 @@ VERSION=@BIND9_VERSION@
 CINCLUDES = -I${srcdir}/include ${ISC_INCLUDES} ${ISCCC_INCLUDES} \
 	${ISCCFG_INCLUDES} ${DNS_INCLUDES} ${BIND9_INCLUDES}
 
-CDEFINES =
+CDEFINES =	@CRYPTO@
 CWARNINGS =
 
 ISCCFGLIBS =	../../lib/isccfg/libisccfg.@A@
diff --git a/bin/confgen/unix/Makefile.in b/bin/confgen/unix/Makefile.in
index 64e3cb8bb5..af1452dbb3 100644
--- a/bin/confgen/unix/Makefile.in
+++ b/bin/confgen/unix/Makefile.in
@@ -16,7 +16,7 @@ top_srcdir =	@top_srcdir@
 CINCLUDES =	-I${srcdir}/include -I${srcdir}/../include \
 		${DNS_INCLUDES} ${ISC_INCLUDES}
 
-CDEFINES =
+CDEFINES =	@CRYPTO@
 CWARNINGS =
 
 OBJS =		os.@O@
diff --git a/bin/pkcs11/Makefile.in b/bin/pkcs11/Makefile.in
index d33fc2094a..e932518943 100644
--- a/bin/pkcs11/Makefile.in
+++ b/bin/pkcs11/Makefile.in
@@ -15,7 +15,7 @@ top_srcdir =	@top_srcdir@
 
 CINCLUDES =	${ISC_INCLUDES}
 
-CDEFINES =
+CDEFINES =	@CRYPTO@
 
 ISCLIBS =	../../lib/isc/libisc.@A@ @ISC_OPENSSL_LIBS@
 
diff --git a/bin/rndc/Makefile.in b/bin/rndc/Makefile.in
index ba68e781f8..51983483a9 100644
--- a/bin/rndc/Makefile.in
+++ b/bin/rndc/Makefile.in
@@ -18,7 +18,7 @@ VERSION=@BIND9_VERSION@
 CINCLUDES = -I${srcdir}/include ${ISC_INCLUDES} ${ISCCC_INCLUDES} \
 	${ISCCFG_INCLUDES} ${DNS_INCLUDES} ${BIND9_INCLUDES}
 
-CDEFINES =
+CDEFINES =	@CRYPTO@
 CWARNINGS =
 
 ISCCFGLIBS =	../../lib/isccfg/libisccfg.@A@
diff --git a/bin/tests/pkcs11/Makefile.in b/bin/tests/pkcs11/Makefile.in
index 73e0596705..29b1f3f0c7 100644
--- a/bin/tests/pkcs11/Makefile.in
+++ b/bin/tests/pkcs11/Makefile.in
@@ -17,7 +17,7 @@ PROVIDER =	@PKCS11_PROVIDER@
 
 CINCLUDES =	${ISC_INCLUDES}
 
-CDEFINES =	-DPK11_LIB_LOCATION=\"${PROVIDER}\"
+CDEFINES =	-DPK11_LIB_LOCATION=\"${PROVIDER}\" @CRYPTO@
 
 ISCLIBS =	../../../lib/isc/libisc.@A@ @ISC_OPENSSL_LIBS@
 
diff --git a/bin/tests/pkcs11/benchmarks/Makefile.in b/bin/tests/pkcs11/benchmarks/Makefile.in
index 15f5460044..3ee3821eec 100644
--- a/bin/tests/pkcs11/benchmarks/Makefile.in
+++ b/bin/tests/pkcs11/benchmarks/Makefile.in
@@ -17,7 +17,7 @@ PROVIDER =	@PKCS11_PROVIDER@
 
 CINCLUDES =	${ISC_INCLUDES}
 
-CDEFINES =	-DPK11_LIB_LOCATION=\"${PROVIDER}\"
+CDEFINES =	-DPK11_LIB_LOCATION=\"${PROVIDER}\" @CRYPTO@
 
 ISCLIBS =	../../../../lib/isc/libisc.@A@ @ISC_OPENSSL_LIBS@
 
diff --git a/bin/tests/system/Makefile.in b/bin/tests/system/Makefile.in
index a552f4667e..d40917fab7 100644
--- a/bin/tests/system/Makefile.in
+++ b/bin/tests/system/Makefile.in
@@ -19,7 +19,7 @@ SUBDIRS =	dlzexternal dyndb pipelined rndc rpz rsabigexponent tkey
 
 CINCLUDES =	${ISC_INCLUDES} ${DNS_INCLUDES}
 
-CDEFINES =	@USE_GSSAPI@
+CDEFINES =	@USE_GSSAPI@ @CRYPTO@
 CWARNINGS =
 
 DNSLIBS =
diff --git a/bin/tests/system/rndc/Makefile.in b/bin/tests/system/rndc/Makefile.in
index 999c1e6e9f..000958b21f 100644
--- a/bin/tests/system/rndc/Makefile.in
+++ b/bin/tests/system/rndc/Makefile.in
@@ -17,7 +17,7 @@ VERSION=@BIND9_VERSION@
 
 CINCLUDES =	${ISC_INCLUDES}
 
-CDEFINES =
+CDEFINES =	@CRYPTO@
 CWARNINGS =
 
 ISCLIBS =	../../../../lib/isc/libisc.@A@ @ISC_OPENSSL_LIBS@
diff --git a/bin/tests/system/rpz/Makefile.in b/bin/tests/system/rpz/Makefile.in
index 9ec63448cd..f44619dfc2 100644
--- a/bin/tests/system/rpz/Makefile.in
+++ b/bin/tests/system/rpz/Makefile.in
@@ -17,7 +17,7 @@ VERSION=@BIND9_VERSION@
 
 CINCLUDES =     ${ISC_INCLUDES} ${DNS_INCLUDES}
 
-CDEFINES =
+CDEFINES =	@CRYPTO@
 CWARNINGS =
 
 DNSLIBS =
diff --git a/contrib/dlz/bin/dlzbdb/Makefile.in b/contrib/dlz/bin/dlzbdb/Makefile.in
index abda98d107..8c9823c97a 100644
--- a/contrib/dlz/bin/dlzbdb/Makefile.in
+++ b/contrib/dlz/bin/dlzbdb/Makefile.in
@@ -17,7 +17,7 @@ DLZINCLUDES =	@DLZ_DRIVER_INCLUDES@
 CINCLUDES =	-I${srcdir}/include -I${srcdir}/unix/include \
                 ${ISC_INCLUDES} ${DLZINCLUDES}
 
-CDEFINES =      @CONTRIB_DLZ@
+CDEFINES =      @CONTRIB_DLZ@ @CRYPTO@
 CWARNINGS =
 
 DLZLIBS = 	@DLZ_DRIVER_LIBS@
diff --git a/lib/irs/tests/Makefile.in b/lib/irs/tests/Makefile.in
index f1bd3c01c4..c4e3b7fdb5 100644
--- a/lib/irs/tests/Makefile.in
+++ b/lib/irs/tests/Makefile.in
@@ -20,7 +20,7 @@ VERSION=@BIND9_VERSION@
 @BIND9_MAKE_INCLUDES@
 
 CINCLUDES =	-I. -Iinclude -I../include ${ISC_INCLUDES} ${IRS_INCLUDES}
-CDEFINES =	-DTESTS="\"${top_builddir}/lib/irs/tests/\""
+CDEFINES =	-DTESTS="\"${top_builddir}/lib/irs/tests/\"" @CRYPTO@
 
 CFGLIBS =	../../isccfg/libisccfg.@A@
 CFGDEPLIBS =	../../isccfg/libisccfg.@A@
diff --git a/lib/isc/include/isc/platform.h.in b/lib/isc/include/isc/platform.h.in
index 9a74ee64d5..822cbead76 100644
--- a/lib/isc/include/isc/platform.h.in
+++ b/lib/isc/include/isc/platform.h.in
@@ -18,6 +18,14 @@
  ***** Platform-dependent defines.
  *****/
 
+/***
+ *** Enforce OpenSSL or PKCS#11 cryptography
+ ***/
+
+#if !defined(OPENSSL) && !defined(PKCS11CRYPTO)
+#error No cryptography library has been found or provided.
+#endif
+
 /***
  *** Network.
  ***/
diff --git a/lib/isc/nls/Makefile.in b/lib/isc/nls/Makefile.in
index 704deadbea..1acb767561 100644
--- a/lib/isc/nls/Makefile.in
+++ b/lib/isc/nls/Makefile.in
@@ -16,7 +16,7 @@ CINCLUDES =	-I../unix/include \
 		-I../include \
 		-I${srcdir}/../include
 
-CDEFINES =
+CDEFINES =	@CRYPTO@
 CWARNINGS =
 
 OBJS =		msgcat.@O@
diff --git a/lib/isc/nothreads/Makefile.in b/lib/isc/nothreads/Makefile.in
index c79477363e..9f20d59831 100644
--- a/lib/isc/nothreads/Makefile.in
+++ b/lib/isc/nothreads/Makefile.in
@@ -17,7 +17,7 @@ CINCLUDES =	-I${srcdir}/include \
 		-I${srcdir}/../include \
 		-I${srcdir}/..
 
-CDEFINES =
+CDEFINES =	@CRYPTO@
 CWARNINGS =
 
 THREADOPTOBJS = condition.@O@ mutex.@O@
diff --git a/lib/isc/pthreads/Makefile.in b/lib/isc/pthreads/Makefile.in
index af4fd6ec29..c3ba6a04e3 100644
--- a/lib/isc/pthreads/Makefile.in
+++ b/lib/isc/pthreads/Makefile.in
@@ -17,7 +17,7 @@ CINCLUDES =	-I${srcdir}/include \
 		-I${srcdir}/../include \
 		-I${srcdir}/..
 
-CDEFINES =
+CDEFINES =	@CRYPTO@
 CWARNINGS =
 
 OBJS =		condition.@O@ mutex.@O@ thread.@O@
diff --git a/lib/isc/win32/Makefile.in b/lib/isc/win32/Makefile.in
index 19b46bdec4..1c5d56793b 100644
--- a/lib/isc/win32/Makefile.in
+++ b/lib/isc/win32/Makefile.in
@@ -15,7 +15,7 @@ CINCLUDES =	-I${srcdir}/.. \
 		-I./include \
 		-I${srcdir}/include \
 		-I${srcdir}/../include
-CDEFINES =
+CDEFINES =	@CRYPTO@
 CWARNINGS =
 
 # Alphabetically
diff --git a/lib/isc/win32/include/isc/platform.h.in b/lib/isc/win32/include/isc/platform.h.in
index d7f94a6ff0..b34e99b3e2 100644
--- a/lib/isc/win32/include/isc/platform.h.in
+++ b/lib/isc/win32/include/isc/platform.h.in
@@ -31,6 +31,14 @@
 #endif
 #endif
 
+/***
+ *** Enforce OpenSSL or PKCS#11 cryptography
+ ***/
+
+#if !defined(OPENSSL) && !defined(PKCS11CRYPTO)
+#error No cryptography library has been found or provided.
+#endif
+
 /***
  *** Network.
  ***/
diff --git a/lib/isccfg/Makefile.in b/lib/isccfg/Makefile.in
index 4625fcd97b..62dbef000a 100644
--- a/lib/isccfg/Makefile.in
+++ b/lib/isccfg/Makefile.in
@@ -19,7 +19,7 @@ VERSION=@BIND9_VERSION@
 
 CINCLUDES =	-I. ${DNS_INCLUDES} ${ISC_INCLUDES} ${ISCCFG_INCLUDES}
 
-CDEFINES =
+CDEFINES =	@CRYPTO@
 CWARNINGS =
 
 ISCLIBS =	../../lib/isc/libisc.@A@ @ISC_OPENSSL_LIBS@
diff --git a/lib/ns/Makefile.in b/lib/ns/Makefile.in
index e81eeb3367..1b26c0cbca 100644
--- a/lib/ns/Makefile.in
+++ b/lib/ns/Makefile.in
@@ -28,7 +28,7 @@ CINCLUDES =	-I. -I${top_srcdir}/lib/ns -Iinclude \
 		${NS_INCLUDES} ${DNS_INCLUDES} ${ISC_INCLUDES} \
 		@DST_OPENSSL_INC@ @DST_GSSAPI_INC@
 
-CDEFINES =
+CDEFINES =	@CRYPTO@
 
 CWARNINGS =
 
diff --git a/lib/samples/Makefile-postinstall.in b/lib/samples/Makefile-postinstall.in
index cf114da6a1..8d5421f98c 100644
--- a/lib/samples/Makefile-postinstall.in
+++ b/lib/samples/Makefile-postinstall.in
@@ -11,7 +11,7 @@ srcdir =	@srcdir@
 #prefix =	@prefix@
 #exec_prefix =	@exec_prefix@
 
-CDEFINES =
+CDEFINES =	@CRYPTO@
 CWARNINGS =
 
 DNSLIBS =	-ldns @DNS_CRYPTO_LIBS@