diff --git a/rotagen.c b/rotagen.c
index 8ff073b..06a556e 100644
--- a/rotagen.c
+++ b/rotagen.c
@@ -83,23 +83,27 @@ int main(void)
 
 void generate_rota(struct slot_result *rota_out)
 {
+	int prev[MAX_JOBS];
+	for (int job = 0; job < num_jobs; ++job)
+		prev[job] = num_people;
+
 	for (int slot = 0; slot < num_slots; ++slot) {
 		do {
-			for (int j = 0; j < num_jobs; ++j) {
-				struct allocation *allocation = &rota_out[slot].allocations[j];
+			for (int job = 0; job < num_jobs; ++job) {
+				struct allocation *allocation
+				    = &rota_out[slot].allocations[job];
 				do {
-					generate_allocation(slot, j, allocation);
-				} while (!satisfies_allocation_constraints(allocation));
+					allocation->slot = slot;
+					allocation->job = job;
+					allocation->person = rand() % num_people;
+				} while (!satisfies_allocation_constraints(allocation)
+				         || previously_allocated(prev, allocation->person));
 			}
 		} while (!satisfies_slot_constraints(&rota_out[slot]));
-	}
-}
 
-void generate_allocation(int slot, int job, struct allocation *allocation_out)
-{
-	allocation_out->slot = slot;
-	allocation_out->job = job;
-	allocation_out->person = rand() % num_people;
+		for (int job = 0; job < num_jobs; ++job)
+			prev[job] = rota_out[slot].allocations[job].person;
+	}
 }
 
 bool satisfies_allocation_constraints(const struct allocation *allocation)
@@ -127,6 +131,15 @@ bool satisfies_allocation_constraints(const struct allocation *allocation)
 	return true;
 }
 
+bool previously_allocated(int prev[MAX_JOBS], int person)
+{
+	for (int job = 0; job < num_jobs; ++job) {
+		if (prev[job] == person)
+			return true;
+	}
+	return false;
+}
+
 bool satisfies_slot_constraints(const struct slot_result *result)
 {
 	for (int i = 0; i < num_jobs; ++i) {
diff --git a/rotagen.h b/rotagen.h
index 863c731..ff09fe3 100644
--- a/rotagen.h
+++ b/rotagen.h
@@ -32,6 +32,7 @@ struct slot_result {
 void generate_rota(struct slot_result *rota_out);
 void generate_allocation(int slot, int job, struct allocation *allocation_out);
 bool satisfies_allocation_constraints(const struct allocation *allocation);
+bool previously_allocated(int previous_allocations[MAX_JOBS], int person);
 bool satisfies_slot_constraints(const struct slot_result *slot);
 void print_rota(const struct slot_result *rota);