diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0fb5cb28f..8deeb37e5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -80,10 +80,7 @@ endif()
 
 if(${CMAKE_SYSTEM} MATCHES "Darwin")
 	add_definitions(-DMACOSX)
-	if(${CMAKE_C_COMPILER_ID} MATCHES "Clang")
-		set(CLANG ON)
 	endif()
-endif()
 
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin")
 set(CMAKE_PDB_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin")
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 3405e85d4..d9e25dbb8 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -408,6 +408,10 @@ if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
 	set(CMAKE_C_FLAGS ${CMAKE_C_FLAGS} -mno-ms-bitfields)
 endif()
 
+if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+	set(CMAKE_C_FLAGS ${CMAKE_C_FLAGS} -Wno-absolute-value)
+endif()
+
 add_definitions(-DCMAKECONFIG)
 
 #add_library(SRB2Core STATIC
diff --git a/src/b_bot.c b/src/b_bot.c
index 5e62e58e6..3072b1d75 100644
--- a/src/b_bot.c
+++ b/src/b_bot.c
@@ -49,7 +49,7 @@ static inline void B_BuildTailsTiccmd(mobj_t *sonic, mobj_t *tails, ticcmd_t *cm
 		if (sonic->player->pflags & (PF_MACESPIN|PF_ITEMHANG))
 		{
 			cmd->forwardmove = sonic->player->cmd.forwardmove;
-			cmd->angleturn = abs(tails->angle - sonic->angle)>>16;
+			cmd->angleturn = abs((tails->angle - sonic->angle))>>16;
 			if (sonic->angle < tails->angle)
 				cmd->angleturn = -cmd->angleturn;
 		} else if (dist > FixedMul(512*FRACUNIT, tails->scale))
diff --git a/src/p_map.c b/src/p_map.c
index 62cbf7b77..1aa8bc391 100644
--- a/src/p_map.c
+++ b/src/p_map.c
@@ -2507,8 +2507,8 @@ isblocking:
 
 			climbangle += (ANGLE_90 * (whichside ? -1 : 1));
 
-			if (((!slidemo->player->climbing && abs(slidemo->angle - ANGLE_90 - climbline) < ANGLE_45)
-			|| (slidemo->player->climbing == 1 && abs(slidemo->angle - climbline) < ANGLE_135))
+			if (((!slidemo->player->climbing && abs((slidemo->angle - ANGLE_90 - climbline)) < ANGLE_45)
+			|| (slidemo->player->climbing == 1 && abs((slidemo->angle - climbline)) < ANGLE_135))
 			&& P_IsClimbingValid(slidemo->player, climbangle))
 			{
 				slidemo->angle = climbangle;
diff --git a/src/p_user.c b/src/p_user.c
index 6844d2cba..dacef733b 100644
--- a/src/p_user.c
+++ b/src/p_user.c
@@ -7902,9 +7902,9 @@ boolean P_MoveChaseCamera(player_t *player, camera_t *thiscam, boolean resetcall
 		if (player == &players[consoleplayer])
 		{
 			if (focusangle >= localangle)
-				localangle += abs(focusangle - localangle)>>5;
+				localangle += abs((focusangle - localangle))>>5;
 			else
-				localangle -= abs(focusangle - localangle)>>5;
+				localangle -= abs((focusangle - localangle))>>5;
 		}
 	}
 	else if (P_AnalogMove(player)) // Analog