diff --git a/doc/guix.texi b/doc/guix.texi
index 7665ec9610..5cdbc5deb6 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -604,7 +604,7 @@ a writable @file{/tmp} directory.
 
 You can influence the directory where the daemon stores build trees
 @i{via} the @code{TMPDIR} environment variable.  However, the build tree
-within the chroot is always @file{/tmp/nix-build-@var{name}.drv-0},
+within the chroot is always @file{/tmp/guix-build-@var{name}.drv-0},
 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
 This way, the value of @code{TMPDIR} does not leak inside build
 environments, which avoids discrepancies in cases where build processes
diff --git a/nix/libstore/build.cc b/nix/libstore/build.cc
index ff7b2c4771..f9fd61adde 100644
--- a/nix/libstore/build.cc
+++ b/nix/libstore/build.cc
@@ -1713,11 +1713,11 @@ void DerivationGoal::startBuilder()
     /* Create a temporary directory where the build will take
        place. */
     auto drvName = storePathToName(drvPath);
-    tmpDir = createTempDir("", "nix-build-" + drvName, false, false, 0700);
+    tmpDir = createTempDir("", "guix-build-" + drvName, false, false, 0700);
 
     /* In a sandbox, for determinism, always use the same temporary
        directory. */
-    tmpDirInSandbox = useChroot ? "/tmp/nix-build-" + drvName + "-0" : tmpDir;
+    tmpDirInSandbox = useChroot ? "/tmp/guix-build-" + drvName + "-0" : tmpDir;
 
     /* For convenience, set an environment pointing to the top build
        directory. */