diff --git a/src/pipupgrade/_pip.py b/src/pipupgrade/_pip.py
index a765db7..23f100e 100644
--- a/src/pipupgrade/_pip.py
+++ b/src/pipupgrade/_pip.py
@@ -43,9 +43,9 @@ def _get_pip_executable(multiple = False):
         exec_ = which(pip_)
         if exec_:
             if not multiple:
-                return exec_
+                return '"' + exec_ + '"'
             else:
-                exec_ = osp.realpath(exec_)
+                exec_ = '"' + osp.realpath(exec_) + '"'
                 if exec_ not in execs:
                     execs.append(exec_)
 
diff --git a/src/pipupgrade/commands/__init__.py b/src/pipupgrade/commands/__init__.py
index 0bcd1ad..4e2b53a 100644
--- a/src/pipupgrade/commands/__init__.py
+++ b/src/pipupgrade/commands/__init__.py
@@ -144,7 +144,7 @@ def _command(*args, **kwargs):
         cli.echo(cli_format("Checking...", cli.YELLOW), file = file_)
 
         pip_path    = a.pip_path or [ ]
-        pip_path    = [which(p) for p in pip_path] or _pip._PIP_EXECUTABLES
+        pip_path    = ['"' + which(p) + '"' for p in pip_path] or _pip._PIP_EXECUTABLES
 
         logger.info("`pip` executables found: %s" % pip_path)