diff --git a/networkapi/api_rack/provision.py b/networkapi/api_rack/provision.py
index ebb228b5..e4d6d634 100644
--- a/networkapi/api_rack/provision.py
+++ b/networkapi/api_rack/provision.py
@@ -419,15 +419,15 @@ def spine_provision(self, rack, equips):
 
                         counter = 1
                         for ipv6 in IPSPINEipv6[numero_rack]:
-                            variablestochangespine1[f'IPSPINE{counter}IPV6'] = ipv6
-                            variablestochangespine1[f"IPNEIGHLEAF{counter}IPV6"] = str(IPLEAFipv6[numero_rack][counter -1])
+                            variablestochangespine1["IPSPINE{}IPV6".format(counter)] = str(ipv6)
+                            variablestochangespine1["IPNEIGHLEAF{}IPV6".format(counter)] = str(IPLEAFipv6[numero_rack][counter -1])
 
                             counter += 1
 
                         counter = 1
                         for ipv4 in IPSPINEipv4[numero_rack]:
-                            variablestochangespine1[f'IPSPINE{counter}IPV4'] = str(ipv6)
-                            variablestochangespine1[f"IPNEIGHLEAF{counter}IPV4"] = str(IPLEAFipv4[numero_rack][counter -1])
+                            variablestochangespine1["IPSPINE{}IPV4".format(counter)] = str(ipv6)
+                            variablestochangespine1["IPNEIGHLEAF{}IPV4".format(counter)] = str(IPLEAFipv4[numero_rack][counter -1])
 
                             counter += 1
 
@@ -443,14 +443,14 @@ def spine_provision(self, rack, equips):
                         variablestochangespine1["VLANFE2LEAF"] = str(vlanFE[spine_num - 2])
                         counter = 1
                         for ipv6 in IPSPINEipv6[numero_rack]:
-                            variablestochangespine1[f'IPSPINE{counter}IPV6'] = str(ipv6)
-                            variablestochangespine1[f"IPNEIGHLEAF{counter}IPV6"] = str(IPLEAFipv6[numero_rack][counter - 1])
+                            variablestochangespine1["IPSPINE{}IPV6".format(counter)] = str(ipv6)
+                            variablestochangespine1["IPNEIGHLEAF{}IPV6".format(counter)] = str(IPLEAFipv6[numero_rack][counter - 1])
                             counter += 1
 
                         counter = 1
                         for ipv4 in IPSPINEipv4[numero_rack]:
-                            variablestochangespine1[f'IPSPINE{counter}IPV4'] = str(ipv6)
-                            variablestochangespine1[f"IPNEIGHLEAF{counter}IPV4"] = str(IPLEAFipv4[numero_rack][counter - 1])
+                            variablestochangespine1["IPSPINE{}IPV4".format(counter)] = str(ipv6)
+                            variablestochangespine1["IPNEIGHLEAF{}IPV4".format(counter)] = str(IPLEAFipv4[numero_rack][counter - 1])
 
 
                             counter += 1