diff --git a/powerlevel9k.zsh-theme b/powerlevel9k.zsh-theme
index 1f13ee5f..c0107eab 100755
--- a/powerlevel9k.zsh-theme
+++ b/powerlevel9k.zsh-theme
@@ -1271,16 +1271,18 @@ prompt_root_indicator() {
 ################################################################
 # Segment to display Rust version number
 prompt_rust_version() {
-  local rust_version
-  rust_version=$(rustc --version 2>&1 | grep -oe "^rustc\s*[^ ]*" | grep -o '[0-9.a-z\\\-]*$')
-  
+  local rust_version=$(command rustc --version 2>/dev/null)
+  # Remove "rustc " (including the whitespace) from the beginning
+  # of the version string and remove everything after the next
+  # whitespace. This way we'll end up with only the version.
+  rust_version=${${rust_version/rustc /}%% *}
+
   if [[ -n "$rust_version" ]]; then
     "$1_prompt_segment" "$0" "$2" "darkorange" "$DEFAULT_COLOR" "$rust_version" 'RUST_ICON'
   fi
 }
 
-################################################################
-# Segment to display RSpec test ratio
+# RSpec test ratio
 prompt_rspec_stats() {
   if [[ (-d app && -d spec) ]]; then
     local code_amount tests_amount
diff --git a/test/segments/rust_version.spec b/test/segments/rust_version.spec
index eb1db35e..2a344f64 100755
--- a/test/segments/rust_version.spec
+++ b/test/segments/rust_version.spec
@@ -5,29 +5,39 @@
 setopt shwordsplit
 SHUNIT_PARENT=$0
 
+TEST_BASE_FOLDER=/tmp/powerlevel9k-test
+RUST_TEST_FOLDER="${TEST_BASE_FOLDER}/rust-test"
+
 function setUp() {
+  OLDPATH="${PATH}"
+  mkdir -p "${RUST_TEST_FOLDER}"
+  PATH="${RUST_TEST_FOLDER}:${PATH}"
+
   export TERM="xterm-256color"
   # Load Powerlevel9k
   source powerlevel9k.zsh-theme
 }
 
+function tearDown() {
+  PATH="${OLDPATH}"
+  rm -fr "${TEST_BASE_FOLDER}"
+}
+
 function mockRust() {
-  echo 'rustc  0.4.1a-alpha'
+  echo "#!/bin/sh\n\necho 'rustc 0.4.1a-alpha'" > "${RUST_TEST_FOLDER}/rustc"
+  chmod +x "${RUST_TEST_FOLDER}/rustc"
 }
 
 function testRust() {
-  alias rustc=mockRust
+  mockRust
   POWERLEVEL9K_LEFT_PROMPT_ELEMENTS=(rust_version)
 
   assertEquals "%K{208} %F{black%}Rust%f %F{black}0.4.1a-alpha %k%F{darkorange}%f " "$(build_left_prompt)"
 
-
   unset POWERLEVEL9K_LEFT_PROMPT_ELEMENTS
-  unalias rustc
 }
 
 function testRustPrintsNothingIfRustIsNotAvailable() {
-  alias rustc=noRust
   POWERLEVEL9K_CUSTOM_WORLD='echo world'
   POWERLEVEL9K_LEFT_PROMPT_ELEMENTS=(custom_world rust_version)
 
@@ -35,7 +45,6 @@ function testRustPrintsNothingIfRustIsNotAvailable() {
 
   unset POWERLEVEL9K_LEFT_PROMPT_ELEMENTS
   unset POWERLEVEL9K_CUSTOM_WORLD
-  unalias rustc
 }
 
 source shunit2/source/2.1/src/shunit2