diff --git a/example-app/Cargo.toml b/example-app/Cargo.toml
index 6038683..4cfce95 100644
--- a/example-app/Cargo.toml
+++ b/example-app/Cargo.toml
@@ -18,7 +18,7 @@ ureq = "2.7.1"
 petgraph = "0.6.3" # for prost_build
 prost-types = "0.12" # for prost_build
 itertools = "0.12.0" # for prost_build
-multimap = "0.9.0" # for prost_build
+multimap = "0.10.0" # for prost_build
 lazy_static = "1.4.0" # for prost_build
 heck = "0.4.1" # for prost_build
 regex = "1.9.3" # for prost_build
@@ -33,7 +33,7 @@ prost = "0.12"
 petgraph = "0.6.3" # for prost_build
 prost-types = "0.12" # for prost_build
 itertools = "0.12.0" # for prost_build
-multimap = "0.9.0" # for prost_build
+multimap = "0.10.0" # for prost_build
 lazy_static = "1.4.0" # for prost_build
 heck = "0.4.1" # for prost_build
 regex = "1.9.3" # for prost_build