diff --git a/tests/hwsim/hostapd.py b/tests/hwsim/hostapd.py
index 9deab15aa..69d3e3135 100644
--- a/tests/hwsim/hostapd.py
+++ b/tests/hwsim/hostapd.py
@@ -55,7 +55,7 @@ class HostapdGlobal:
                                     stdout=subprocess.PIPE, shell=shell)
             out = proc.communicate()[0]
             ret = proc.returncode
-            return ret, out
+            return ret, out.decode()
         else:
             return self.host.execute(cmd_array)
 
@@ -162,7 +162,7 @@ class Hostapd:
                                     stdout=subprocess.PIPE, shell=shell)
             out = proc.communicate()[0]
             ret = proc.returncode
-            return ret, out
+            return ret, out.decode()
         else:
             return self.host.execute(cmd_array)
 
diff --git a/tests/hwsim/remotehost.py b/tests/hwsim/remotehost.py
index bf1ccd216..f18da4994 100644
--- a/tests/hwsim/remotehost.py
+++ b/tests/hwsim/remotehost.py
@@ -55,7 +55,7 @@ class Host():
 
         logger.debug("status: " + str(status))
         logger.debug("buf: " + str(buf))
-        return status, buf
+        return status, buf.decode()
 
     def execute(self, command):
         if self.host is None:
@@ -73,7 +73,7 @@ class Host():
 
         logger.debug(self.name + " status: " + str(status))
         logger.debug(self.name + " buf: " + str(buf))
-        return status, buf
+        return status, buf.decode()
 
     # async execute
     def execute_run(self, command, res):
diff --git a/tests/hwsim/wpasupplicant.py b/tests/hwsim/wpasupplicant.py
index 0cc6ea8c9..1d538f1f7 100644
--- a/tests/hwsim/wpasupplicant.py
+++ b/tests/hwsim/wpasupplicant.py
@@ -64,7 +64,7 @@ class WpaSupplicant:
                                     stdout=subprocess.PIPE, shell=shell)
             out = proc.communicate()[0]
             ret = proc.returncode
-            return ret, out
+            return ret, out.decode()
         else:
             return self.host.execute(cmd_array)