diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index c379a0b996f..781ba594265 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -603,18 +603,20 @@ target_link_libraries (gshhg_version ${NETCDF_LIBRARIES})
 # script2verbatim for removing comments, replacing -ps from example scripts
 add_executable (script2verbatim script2verbatim.c)
 
-option(WITH_GMT_UPDATE "Build and install gmt_update executable" ON)
-if (WITH_GMT_UPDATE)
-	# gmt_update — standalone binary updater. Deliberately does NOT link against
-	# libgmt/pslib so that those DLLs are NOT held open by this process and can be
-	# replaced on Windows. Uses only libcurl + an embedded public-domain SHA-256.
-	add_executable (gmt_update gmt_update.c sha256.c)
-	target_include_directories (gmt_update PRIVATE ${CURL_INCLUDE_DIRS})
-	target_link_libraries (gmt_update ${CURL_LIBRARIES})
-	if (WIN32)
-		target_link_libraries (gmt_update rstrtmgr)
-	endif (WIN32)
-	install (TARGETS gmt_update RUNTIME DESTINATION ${GMT_BINDIR} COMPONENT Runtime)
+if (MSVC)
+	option(WITH_GMT_UPDATE "Build and install gmt_update executable" ON)
+	if (WITH_GMT_UPDATE)
+		# gmt_update — standalone binary updater. Deliberately does NOT link against
+		# libgmt/pslib so that those DLLs are NOT held open by this process and can be
+		# replaced on Windows. Uses only libcurl + an embedded public-domain SHA-256.
+		add_executable (gmt_update gmt_update.c sha256.c)
+		target_include_directories (gmt_update PRIVATE ${CURL_INCLUDE_DIRS})
+		target_link_libraries (gmt_update ${CURL_LIBRARIES})
+		if (WIN32)
+			target_link_libraries (gmt_update rstrtmgr)
+		endif (WIN32)
+		install (TARGETS gmt_update RUNTIME DESTINATION ${GMT_BINDIR} COMPONENT Runtime)
+	endif()
 endif()