diff --git a/src/libstore/derivations.hh b/src/libstore/derivations.hh
index 7ee3ded6a..f42c13cdc 100644
--- a/src/libstore/derivations.hh
+++ b/src/libstore/derivations.hh
@@ -13,6 +13,7 @@
 
 namespace nix {
 
+class Store;
 
 /* Abstract syntax of derivations. */
 
diff --git a/src/libstore/path.hh b/src/libstore/path.hh
index 0694b4c18..8e1cb5e55 100644
--- a/src/libstore/path.hh
+++ b/src/libstore/path.hh
@@ -5,7 +5,6 @@
 
 namespace nix {
 
-class Store;
 struct Hash;
 
 class StorePath
diff --git a/src/libstore/realisation.hh b/src/libstore/realisation.hh
index 911c61909..62561fce3 100644
--- a/src/libstore/realisation.hh
+++ b/src/libstore/realisation.hh
@@ -7,6 +7,8 @@
 
 namespace nix {
 
+class Store;
+
 struct DrvOutput {
     // The hash modulo of the derivation
     Hash drvHash;