diff --git a/CMakeLists.txt b/CMakeLists.txt
index e6b472150..5a8147a51 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -111,6 +111,17 @@ if(NOT DEFINED EXPORT_ALL_SYMBOLS)
 	set(EXPORT_ALL_SYMBOLS TRUE)
 endif()
 
+# BSD
+if(${CMAKE_SYSTEM_NAME} MATCHES "BSD")
+	set(BSD TRUE)
+	if(${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD")
+		set(FREEBSD TRUE)
+	endif()
+	if(${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD")
+		set(OPENBSD TRUE)
+	endif()
+endif()
+
 # Configure MSVC Runtime
 if(MSVC)
 	include(MSVCRuntime)
@@ -179,14 +190,17 @@ if(CMAKE_COMPILER_IS_GNUCC)
 	if(Wimplicit-function-declaration)
 		set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wimplicit-function-declaration")
 	endif()
-	CHECK_C_COMPILER_FLAG (-Wredundant-decls Wredundant-decls)
-	if(Wredundant-decls)
-		set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wredundant-decls")
+
+	if (NOT OPENBSD)
+		CHECK_C_COMPILER_FLAG (-Wredundant-decls Wredundant-decls)
+		if(Wredundant-decls)
+			set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wredundant-decls")
+		endif()
 	endif()
 	if(CMAKE_BUILD_TYPE STREQUAL "Release")
 		set(CMAKE_C_FLAGS_RELEASE "-DNDEBUG")
 		set(CMAKE_CXX_FLAGS_RELEASE "-DNDEBUG")
-		if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD")
+		if(NOT OPENBSD)
 			set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O2")
 			set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O2")
 		endif()
@@ -360,17 +374,6 @@ if(APPLE)
 	endif()
 endif(APPLE)
 
-# BSD
-if(${CMAKE_SYSTEM_NAME} MATCHES "BSD")
-	set(BSD TRUE)
-	if(${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD")
-		set(FREEBSD TRUE)
-	endif()
-	if(${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD")
-		set(OPENBSD TRUE)
-	endif()
-endif()
-
 # OpenBSD
 if(OPENBSD)
 	set(WITH_ALSA  "OFF")
diff --git a/winpr/libwinpr/crt/alignment.c b/winpr/libwinpr/crt/alignment.c
index c7ec3795a..8bb3f085d 100644
--- a/winpr/libwinpr/crt/alignment.c
+++ b/winpr/libwinpr/crt/alignment.c
@@ -36,7 +36,7 @@
 
 #ifdef __APPLE__
 #include <malloc/malloc.h>
-#elif __FreeBSD__
+#elif __FreeBSD__ || __OpenBSD__
 #include <stdlib.h>
 #else
 #include <malloc.h>