diff --git a/lib/SlackBuilder/Download.hs b/lib/SlackBuilder/Download.hs
index 7729b0b..2dc503d 100644
--- a/lib/SlackBuilder/Download.hs
+++ b/lib/SlackBuilder/Download.hs
@@ -77,7 +77,7 @@ updateSlackBuildVersion packagePath version additionalDownloads = do
     updateLineDependencyVersion dependencyName = updateLineVariable
         $ dependencyName <> "_VERSION"
     updateLineVariable variableName variableValue line
-        | Text.isSuffixOf (variableName <> "=") line =
+        | Text.isPrefixOf (variableName <> "=") line =
             variableName <> "=${" <> variableName <> ":-" <> variableValue <> "}"
         | otherwise = line
 
diff --git a/slackbuilder.cabal b/slackbuilder.cabal
index a6748d4..3334aa0 100644
--- a/slackbuilder.cabal
+++ b/slackbuilder.cabal
@@ -17,7 +17,7 @@ extra-source-files: CHANGELOG.md
 
 common dependencies
   build-depends:
-    base ^>= 4.16.4.0,
+    base >= 4.16 && < 5,
     bytestring ^>= 0.11.0,
     containers ^>= 0.6,
     cryptonite >= 0.30,
@@ -77,7 +77,7 @@ executable slackbuilder
     slackbuilder,
     unordered-containers ^>= 0.2.19,
     vector ^>= 0.13.0
-  hs-source-dirs: app
+  hs-source-dirs: src
 
   ghc-options: -threaded -rtsopts -with-rtsopts=-N -Wall
 
diff --git a/app/Main.hs b/src/Main.hs
similarity index 100%
rename from app/Main.hs
rename to src/Main.hs
diff --git a/app/SlackBuilder/CommandLine.hs b/src/SlackBuilder/CommandLine.hs
similarity index 100%
rename from app/SlackBuilder/CommandLine.hs
rename to src/SlackBuilder/CommandLine.hs
diff --git a/app/SlackBuilder/Updater.hs b/src/SlackBuilder/Updater.hs
similarity index 100%
rename from app/SlackBuilder/Updater.hs
rename to src/SlackBuilder/Updater.hs