diff --git a/lib/tls/CMakeLists.txt b/lib/tls/CMakeLists.txt
index aaf4f4a26..fd3c27fab 100644
--- a/lib/tls/CMakeLists.txt
+++ b/lib/tls/CMakeLists.txt
@@ -254,6 +254,10 @@ if (LWS_WITH_SSL)
 	endif()
 
 	if (NOT chose_ssl)
+		if (OPENSSL_FOUND AND "${OPENSSL_INCLUDE_DIRS}" STREQUAL "")
+			set(OPENSSL_INCLUDE_DIRS "${OPENSSL_INCLUDE_DIR}")
+		endif()
+
 		if (NOT OPENSSL_FOUND AND NOT LWS_WITH_BORINGSSL)
 			# TODO: Add support for STATIC also.
 			if (NOT LWS_PLAT_FREERTOS)