diff --git a/CMakeLists.txt b/CMakeLists.txt
index ab80858d1..c3a68f4da 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -754,13 +754,15 @@ if(UNIX AND EXISTS "/usr/lib64")
 endif()
 if(NOT BOOST_ROOT)
     # Workaround for Macports
-    if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin" AND (${DETECT_MACPORTS} EQUAL 0))
-        if(EXISTS "${MACPORTS_PREFIX}/libexec/boost/1.81")
-            set(BOOST_ROOT "${MACPORTS_PREFIX}/libexec/boost/1.81")
-        elseif(EXISTS "${MACPORTS_PREFIX}/libexec/boost/1.76")
-            set(BOOST_ROOT "${MACPORTS_PREFIX}/libexec/boost/1.76")
-        elseif(EXISTS "${MACPORTS_PREFIX}/libexec/boost/1.71")
-            set(BOOST_ROOT "${MACPORTS_PREFIX}/libexec/boost/1.71")
+    if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
+        if(${DETECT_MACPORTS} EQUAL 0)
+            if(EXISTS "${MACPORTS_PREFIX}/libexec/boost/1.81")
+                set(BOOST_ROOT "${MACPORTS_PREFIX}/libexec/boost/1.81")
+            elseif(EXISTS "${MACPORTS_PREFIX}/libexec/boost/1.76")
+                set(BOOST_ROOT "${MACPORTS_PREFIX}/libexec/boost/1.76")
+            elseif(EXISTS "${MACPORTS_PREFIX}/libexec/boost/1.71")
+                set(BOOST_ROOT "${MACPORTS_PREFIX}/libexec/boost/1.71")
+            endif()
         endif()
     endif()
 endif()