diff --git a/src/base/_foundation.lua b/src/base/_foundation.lua
index b0e700f9d..ce70e6b57 100644
--- a/src/base/_foundation.lua
+++ b/src/base/_foundation.lua
@@ -238,15 +238,7 @@
 --
 
 	function premake.findProjectScript(fname)
-		local with_ext = fname .. ".lua"
-		local p5 = path.join(fname, "premake5.lua")
-		local p4 = path.join(fname, "premake4.lua")
-
-		local res = os.locate(fname, with_ext, p5, p4)
-		if res == nil then
-			premake.error("Cannot find either " .. table.implode({fname, with_ext, p5, p4}, "", "", " or "))
-		end
-		return res
+		return os.locate(fname, fname .. ".lua", path.join(fname, "premake5.lua"), path.join(fname, "premake4.lua"))
 	end
 
 
diff --git a/src/base/api.lua b/src/base/api.lua
index faa8a0a49..29aa546e7 100755
--- a/src/base/api.lua
+++ b/src/base/api.lua
@@ -81,9 +81,10 @@
 ---
 
 	function includeexternal(fname)
-		fname = p.findProjectScript(fname)
+		local fullPath = p.findProjectScript(fname)
 		local wasIncludingExternal = api._isIncludingExternal
 		api._isIncludingExternal = true
+		fname = fullPath or fname
 		dofile(fname)
 		api._isIncludingExternal = wasIncludingExternal
 	end
diff --git a/src/base/globals.lua b/src/base/globals.lua
index 8e54afd16..5946db8d0 100644
--- a/src/base/globals.lua
+++ b/src/base/globals.lua
@@ -48,7 +48,8 @@
 	io._includedFiles = {}
 
 	function include(fname)
-		fname = premake.findProjectScript(fname)
+		local fullPath = premake.findProjectScript(fname)
+		fname = fullPath or fname
 		if not io._includedFiles[fname] then
 			io._includedFiles[fname] = true
 			return dofile(fname)