diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # cdeps
 
+## 0.1.2.3
+
+  * Set `cross` flag to temporarily enable cross-compilation. This will be
+    necessary until cabal handles build tools correctly when cross-compiling.
+
 ## 0.1.2.1
 
   * Improve backwards compatibility
diff --git a/cdeps.cabal b/cdeps.cabal
--- a/cdeps.cabal
+++ b/cdeps.cabal
@@ -1,6 +1,6 @@
 cabal-version: 1.18
 name: cdeps
-version: 0.1.2.2
+version: 0.1.2.3
 license: BSD3
 license-file: LICENSE
 copyright: Copyright: (c) 2018 Vanessa McHale
@@ -18,6 +18,12 @@
     type: darcs
     location: https://hub.darcs.net/vamchale/cdeps
 
+flag cross
+    description:
+        Set this flag when cross-compiling
+    default: False
+    manual: True
+
 flag development
     description:
         Enable `-Werror`
@@ -27,7 +33,6 @@
 library
     exposed-modules:
         Language.C.Dependency
-    build-tools: alex -any
     hs-source-dirs: src
     default-language: Haskell2010
     other-extensions: OverloadedStrings
@@ -39,18 +44,21 @@
         array -any,
         directory -any,
         filepath -any
-    
+
+    if !flag(cross)
+        build-tools: alex -any
+
     if (flag(development) && impl(ghc <8.4))
         ghc-options: -Werror
-    
+
     if !impl(ghc >=8.0)
         build-depends:
             transformers -any,
             semigroups -any
-    
+
     if impl(ghc >=8.0)
         ghc-options: -Wincomplete-uni-patterns -Wincomplete-record-updates
-    
+
     if impl(ghc >=8.4)
         ghc-options: -Wmissing-export-lists
 
@@ -65,17 +73,17 @@
         base >=4.8 && <5,
         cdeps -any,
         optparse-applicative -any
-    
+
     if !impl(ghc >=8.0)
         build-depends:
             semigroups -any
-    
+
     if (flag(development) && impl(ghc <8.4))
         ghc-options: -Werror
-    
+
     if impl(ghc >=8.0)
         ghc-options: -Wincomplete-uni-patterns -Wincomplete-record-updates
-    
+
     if impl(ghc >=8.4)
         ghc-options: -Wmissing-export-lists
 
@@ -89,12 +97,12 @@
         base -any,
         cdeps -any,
         hspec -any
-    
+
     if flag(development)
         ghc-options: -Werror
-    
+
     if impl(ghc >=8.0)
         ghc-options: -Wincomplete-uni-patterns -Wincomplete-record-updates
-    
+
     if impl(ghc >=8.4)
         ghc-options: -Wmissing-export-lists