diff --git a/schemas/blackmarket-v1.0.json b/schemas/blackmarket-v1.0.json
index 5129bd9..362916a 100644
--- a/schemas/blackmarket-v1.0.json
+++ b/schemas/blackmarket-v1.0.json
@@ -44,7 +44,7 @@
                     "minLength"     : 1
                 },                
                 "marketId": {
-                    "type"          : "number"
+                    "type"          : "integer"
                 },
                 "timestamp": {
                     "type"          : "string",
diff --git a/schemas/commodity-v3.0.json b/schemas/commodity-v3.0.json
index f8ea96a..6807638 100644
--- a/schemas/commodity-v3.0.json
+++ b/schemas/commodity-v3.0.json
@@ -43,7 +43,7 @@
                     "minLength" : 1
                 },                
                 "marketId": {
-                    "type"      : "number"
+                    "type"      : "integer"
                 },
                 "horizons": {
                     "type"      : "boolean",
diff --git a/schemas/journal-v1.0.json b/schemas/journal-v1.0.json
index 4ba8770..110639d 100644
--- a/schemas/journal-v1.0.json
+++ b/schemas/journal-v1.0.json
@@ -55,7 +55,7 @@
                     "description"   : "Must be added by the sender if not present in the journal event"
                 },
                 "SystemAddress": {
-                    "type"          : "number",
+                    "type"          : "integer",
                     "description"   : "Should be added by the sender if not present in the journal event"
                 },
 
diff --git a/schemas/outfitting-v2.0.json b/schemas/outfitting-v2.0.json
index 414d190..a654be7 100644
--- a/schemas/outfitting-v2.0.json
+++ b/schemas/outfitting-v2.0.json
@@ -43,7 +43,7 @@
                     "minLength" : 1
                 },                
                 "marketId": {
-                    "type"      : "number"
+                    "type"      : "integer"
                 },
                 "horizons": {
                     "type"      : "boolean",
diff --git a/schemas/shipyard-v2.0.json b/schemas/shipyard-v2.0.json
index 8f2e05a..0eb54fb 100644
--- a/schemas/shipyard-v2.0.json
+++ b/schemas/shipyard-v2.0.json
@@ -43,7 +43,7 @@
                     "minLength" : 1
                 },                
                 "marketId": {
-                    "type"          : "number"
+                    "type"          : "integer"
                 },
                 "horizons": {
                     "type"      : "boolean",