diff --git a/spec/Appendix B -- Grammar Summary.md b/spec/Appendix B -- Grammar Summary.md
index 7afe9e11b..c40662504 100644
--- a/spec/Appendix B -- Grammar Summary.md	
+++ b/spec/Appendix B -- Grammar Summary.md	
@@ -143,7 +143,7 @@ ExecutableDefinition :
 
 OperationDefinition :
 
-- OperationType Name? VariableDefinitions? Directives? SelectionSet
+- OperationType Name? VariablesDefinition? Directives? SelectionSet
 - SelectionSet
 
 OperationType : one of `query` `mutation` `subscription`
@@ -205,7 +205,7 @@ ObjectValue[Const] :
 
 ObjectField[Const] : Name : Value[?Const]
 
-VariableDefinitions : ( VariableDefinition+ )
+VariablesDefinition : ( VariableDefinition+ )
 
 VariableDefinition : Variable : Type DefaultValue? Directives[Const]?
 
diff --git a/spec/Section 2 -- Language.md b/spec/Section 2 -- Language.md
index bd5e1c3d5..c89aaf05e 100644
--- a/spec/Section 2 -- Language.md	
+++ b/spec/Section 2 -- Language.md	
@@ -280,7 +280,7 @@ be executed must also be provided.
 
 OperationDefinition :
 
-- OperationType Name? VariableDefinitions? Directives? SelectionSet
+- OperationType Name? VariablesDefinition? Directives? SelectionSet
 - SelectionSet
 
 OperationType : one of `query` `mutation` `subscription`
@@ -1086,7 +1086,7 @@ ObjectValue : { ObjectField+ }
 
 Variable : $ Name
 
-VariableDefinitions : ( VariableDefinition+ )
+VariablesDefinition : ( VariableDefinition+ )
 
 VariableDefinition : Variable : Type DefaultValue? Directives[Const]?
 
diff --git a/spec/Section 6 -- Execution.md b/spec/Section 6 -- Execution.md
index a0f3400d4..0d7667ba0 100644
--- a/spec/Section 6 -- Execution.md	
+++ b/spec/Section 6 -- Execution.md	
@@ -77,8 +77,8 @@ the operation fails without execution.
 CoerceVariableValues(schema, operation, variableValues):
 
 - Let {coercedValues} be an empty unordered Map.
-- Let {variableDefinitions} be the variables defined by {operation}.
-- For each {variableDefinition} in {variableDefinitions}:
+- Let {variablesDefinition} be the variables defined by {operation}.
+- For each {variableDefinition} in {variablesDefinition}:
   - Let {variableName} be the name of {variableDefinition}.
   - Let {variableType} be the expected type of {variableDefinition}.
   - Assert: {IsInputType(variableType)} must be {true}.